1. Field of the Invention
The present invention relates to a drawer type cooking device in which a heating container that contains an object to be heated can be drawn out of a heating chamber formed in a body of the cooking device by an operation of an open/close door.
2. Description of the Related Art
Conventionally, a cooking device has been proposed including: a device body including a cooking chamber that contains an object to be cooked; an open/close door that blocks off the cooking chamber from outside; a bottom plate that interlocks with the open/close door; a slide mechanism that slides the bottom plate; a motor that drives the bottom plate; transmission means that transmits a drive force of the motor to the bottom plate; a latch device that holds the open/close door in a closed state; a door open/close switch; and a control circuit that controls driving of the motor so as to receive a signal from the door open/close switch and operate the open/close door (Japanese Patent Laid-Open Publication No. 3-45820 (Patent Document 1)). When the door open/close switch is operated, the latch is automatically released, the force of the motor causes the open/close door to interlock with the bottom plate and gradually slide toward a front surface of the device, thereby facilitating loading and unloading of an object to be cooked. The bottom plate is directly connected to a lower portion near a lower side of the open/close door, and sides of the bottom plate are opened when the open/close door is opened. The open/close door that blocks off the cooking chamber from the atmosphere is provided integrally with the bottom plate, and thus when the bottom plate is driven by the motor, the open/close door is interlockingly moved. In the bottom plate, a bent portion is held between a first roller and a second roller provided at each side end, and the bottom plate is integrally provided in a door open/close direction by a third roller provided in a rear portion of the bottom plate.
A cooking device has been also proposed in which a drawer body that contains an object to be heated is drawably provided in a cooking device body, including: detection means for detecting that the drawer body is drawn out; control means for outputting an excitation command signal when a detection signal is provided from the detection means; and an electromagnet leg provided on a bottom surface of the cooking device body and excited when the excitation command signal is provided (Japanese Patent Laid-Open Publication No. 6-109257 (Patent Document 2)). When the drawer body is drawn out, the control means outputs the excitation command signal on the basis of detection by the detection means, and the electromagnet leg provided on the bottom surface of the cooking device body is excited. Movement of the center of gravity caused by drawing easily causes falling over of the entire cooking device, but the electromagnet leg sticks to a metal loading surface of a counter or the like to prevent falling over of the cooking device and allow the drawer type cooking device to be always used in a stable state.
A microwave oven has been also proposed in which a heating container having an opening in an upper portion is provided drawably from a body housing, the heating container and a lid provided on the body housing and covering the opening of the heating container constitute a heating chamber that confines microwaves, and a choke groove is provided between an opening peripheral edge of the heating container and the lid facing the opening peripheral edge to prevent leakage of radio waves, thereby preventing leakage of radio waves even with a drawer structure having a movable food loading portion (Japanese Patent Laid-Open Publication No. 11-237053 (Patent Document 3)). A front surface of the heating container serves as an open/close door that blocks off the heating chamber from outside air.
FIG. 3 is a perspective view of a drawer type cooking device equal to that already proposed by the applicant, and FIG. 4 is a sectional view of a drawer body being drawn out of a cooking device body in the drawer type cooking device shown in FIG. 3. The cooking device body 1 includes a heating chamber 3 for cooking an object to be heated. The drawer body 2 includes an open/close door (hereinafter abbreviated as “door”) 2a for opening and closing the heating chamber 3 and a heating container 2b having a container shape for receiving and containing the object to be heated. The drawer body 2 is placed slidably in the cooking device body 1 by a slide mechanism 4 so as to be drawn forward from an inside of the heating chamber 3 of the cooking device body 1. The slide mechanism 4 is placed on each of right and left side wall surfaces located outside the heating chamber 3. The slide mechanism 4 is provided outside the heating chamber 3, and thus a movable rail 8 and a fixed rail 9 that constitute the slide mechanism 4 need not be formed of expensive components or materials having high heat resistance and flame retardancy, also the slide mechanism 4 is not influenced by microwaves applied in the heating chamber 3, and there is no risk of electric discharge by microwaves (Japanese Patent Publication No. 4027325 (Patent Document 4)).
The slide mechanism 4 includes, though not specifically shown, the fixed rail secured to the cooking device body 1 and the movable rail that slides along the fixed rail. The movable rail is connected to the door 2a, and thus the drawer body 2 is supported slidably via the door 2a and the slide mechanism 4 to the cooking device body 1. To drive the slide mechanism 4, for example, a DC motor is provided as a drive mechanism. Though not specifically shown, a pinion coupled to a rotation output shaft of the DC motor via a transmission mechanism engages a rack mounted to the movable rail, and rotation of the pinion causes a linear motion of the rack to drive the slide mechanism 4 and drive the drawer body 2.
The heating container 2b includes side walls on lateral sides and a rear wall on a back side located in the heating chamber 3 of the cooking device body 1, and an upper portion thereof is an opening for loading and unloading the object to be heated. The door 2a is mounted to a front of the heating container 2b. The door 2a and the heating container 2b are previously assembled and cannot be disassembled in a normal state of use, and serve and are handled as an integral component. The door 2a closes an opening 3a of the heating chamber 3, and thus an inner space of the heating chamber 3 is sealed by an inner wall surface of the cooking device body 1 and the drawer body 2 to prevent leakage of microwaves. The door 2a has an operation unit 9 for opening and closing operations by a user, and the operation unit 9 includes a control portion 5 and an operation button 9a. 
In producing the drawer body provided in the heating chamber that is filled with microwaves during cooking, the door 2a and the heating container 2b that are components of the drawer body are electrically welded and integrated. Electrical welding is selected as connection means because the components can be fastened and joined in a shorter time than by other fastening means to increase productivity and also because electrical joining of metals ensures conductivity or electrical continuity between the components so that the same electric potential is generated in the both components by eddy current electromagnetically induced by microwaves during cooking, thereby preventing discharge between the components. With such a great advantage, the conventional drawer type cooking device uses the structure in which the door 2a and the heating container 2b are electrically welded and integrated.
The heating container part of this drawer body needs heat resistant coating for preventing contamination or corrosion caused by water vapor generated during cooking, droplets from an object to be heated, or condensation water after cooking, but the components with coated surfaces by coating cannot be electrically welded and thus welding needs to be performed before the coating.
In this case, the following coating process is performed.
1. Degreasing (a steel plate is immersed in a degreasing liquid having a function of dissolving oils and fats to remove oils and fats adhering to a surface of the steel plate during press working of the steel plate.)
2. Primer coating (the steel plate as a material is immersed in a primer liquid to form an intermediate conductive film compatible with both a steel plate surface and a coating film on the steel plate surface.)
3. Electrocoating (the steel plate is immersed in an electrolyte tank containing a coating material, and a heat-resistant reliable coating film without a pinhole is formed on a primer film on the steel plate surface by an electrochemical process using a drawer body as an electrode.)
The welded assembly of the drawer body immediately before coating has an irregular shape because the heating container having a rectangular box shape and the open/close door having a plate shape are connected. Thus, when the assembly is immersed and treated in a treatment liquid such as the degreasing liquid, the primer liquid, or the electrolyte as described above in each step, the treatment liquid used in each step remains in a recess or the like in the steel plate and cannot be sufficiently removed, and is carried over to the treatment liquid in the next step as impurity. In addition, the treatment liquid in the previous step remains in the surface of the assembly, which may hinder the treatment in the next step. For example, there is a possibility of a poor coating appearance, that is, a possibility that the degreasing liquid or the primer liquid remains to prevent contact between the steel plate surface and the electrolyte in electrocoating and thus prevent the coating material from adhering to the steel plate surface, or the coating film does not adhere to the steel plate and is easily removed because a film of the degreasing liquid or the primer liquid is interposed therebetween.
Also, when the drawer body having the irregular shape is conveyed between the steps, insertion of a shock absorber or securing of the assembly is difficult, and contact or collision between drawer bodies or between the drawer body and a conveying medium may cause flaws, dents or the like, thereby providing a poor appearance. Preventing such a problem generally requires much more careful confirmation and adjustment than those in assembly and coating of components having simple shapes, which increases a time for coating.
Thus, in the conventional drawer type cooking device, the heating container 2b is integrated with the door 2a, and the heating container 2b is drawable so as to be pushed in and drawn out of the heating chamber 3 of the cooking device body 1. Meanwhile, a wall surface of the heating chamber 3 is contaminated by droplets from the object to be heated with increasing number of cooking. When a back or a corner of the heating container 2b or a ceiling surface of the heating chamber 3 is contaminated, such a portion is hard for a user to visually check and reach in cleaning partly because the drawer type cooking device is installed immediately below a cooking counter, and thus completely cleaning the contamination is difficult.
A panel (metal) of the door 2a that constitutes the open/close door needs surface treatment (coating) to prevent interference with electromagnetic induction by microwaves. However, the heating container 2b is integrated with the door 2a to constitute the drawer body, thus a ceiling surface of the assembly has an uneven height, and stacking is extremely difficult in storage and movement between steps in a production process, there is a high possibility of deformation in carrying, and assembling and setting require a large space, thereby reducing productivity and yield with a high rejection rate.
Thus, there is a problem to be solved for providing a drawer type cooking device in which an open/close door as a front surface and a heating container that receives an object to be heated that are conventionally integrated as a drawer body can be separated from each other without loss of basic performance such as strength required as a drawer body or appearance accuracy.
The present invention has an object to solve the above described problem and provide a drawer type cooking device that allows cleaning of a heating container with a heating container being removed from an open/close door, allows easy cleaning of contamination on an inside of a heating chamber such as a ceiling, and facilitates assembling after individual production and coating or the like of the open/close door and the heating container even in a production stage.